I've just taken my 124 Spider 1975 1800 running 40mm DRLA Dellorto carbs to the rolling road as I'm surfing from a loss of power.
Unfortunately it's still not resolved, any thoughts as the catastrophic loss of power?
The Power is dropping dramatically at about 4,500rpm and then recovers after 5,500 rpm any suggestions?
It's not the carbs, mixture is now good, fuel pressure is OK timing is correct 0" idle and 36" advanced.
Main jest are 150 changed from 135 original.
Suggestions so far are distributor spring bounce, over pressure on fuel pump .
Are 40mm OK for 1800, I've seen conflicting info some say they should be OK others that need 45mm.